Our latest design of a test rig for production acceptance testing (PAT) of the aircraft power drive unit (PDU) for the Airbus A220 might never have occurred if it were not for a strange U-turn as the aircraft size was originally dismissed by Airbus as having no business case.
The Airbus A220 family of aircraft was initially designed by Bombardier Aerospace as the C- Series (CS100 and CS300), it was formally launched at the Farnborough Air Show in July 2008, the smaller of the two (CS100) performed its maiden flight on September 16", 2013, and entered commercial service on July 15th, 2016.
Goodrich Actuation Systems had been chosen for the design and production of a fully integrated high lift flap and slat actuation systems, and the thrust reverser actuation system.
During this period, Comar had worked with Goodrich Actuation Systems (now Collins Aerospace), providing qualification test rigs for the PDU, Flap & Slat Actuators, Thrust Reversers, Track Lock Valve, Outboard Brake, and the complete Half Wing test rig.
A year later, in April 2017, Boeing filed a petition against Bombardier for selling the C-Series aircraft as a loss leader which posed a significant threat to the US aircraft industry, as a result of protracted court cases, the slow business and tough competition it forced Bombardier to enter a partnership with Airbus in October 2017 and the C-Series was rebranded as the Airbus A220.
All the development testing was not wasted, and Goodrich and Comar progressed to designing production test rigs, and as of February 2024, a total of 914 A220s had been ordered of which 322 had been delivered, disproving, Airbus’s original negativity to it being a viable aircraft.
The Power Drive Unit (PDU) is the motive force and control used for the Flap and Slat aircraft flying controls on the aircraft, it is a common part in both Slat and Flap Systems on this aircraft.
Both PDU’s on the aircraft are controlled by the pilot via the aircraft Flap/Slat computer system, it is a hydraulically powered, electrically controlled unit which contains two fully independent drive channels with brakes and isolation valves, coupled with a speed summing differential, the PDU’s provide the transmission system with mechanical power through an output shaft as commanded by the pilot to drive the flap or slat surfaces against air loads.
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